Zhu Lin, Selverston Allen I, Ayers Joseph
Department of Biology, Northeastern University, Boston, MA, 02115, USA.
Marine Science Center, Department of Marine and Environmental Sciences, Northeastern University, Nahant, MA, 01908, USA.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2017 Apr;203(4):275-290. doi: 10.1007/s00359-017-1162-z. Epub 2017 Mar 18.
The crustacean stomatogastric nervous system is a classic model for understanding the effects of modulating ionic currents and synapses at both the cell and network levels. The stomatogastric ganglion in this system contains two distinct central pattern generators: a slow gastric mill network that generates flexible rhythmic outputs (8-20 s) and is often silent, and a fast pyloric network that generates more consistent rhythmic outputs (0.5-2 s) and is always active in vitro. Different ionic conductances contribute to the properties of individual neurons and therefore to the overall dynamics of the pyloric and gastric mill networks. However, the contributions of ionic currents to different dynamics between the pyloric and gastric mill networks are not well understood. The goal of this study is to evaluate how changes in outward potassium current (I ) in the stomatogastric ganglion affect the dynamics of the pyloric and gastric mill rhythms by interfering with normal I activity. We bath-applied the specific I blocker 4-aminopyridine to reduce I 's effect in the stomatogastric ganglion in vitro and evaluated quantitatively the changes in both rhythms. We found that blocking I in the stomatogastric ganglion alters the synchronization between pyloric neurons, and consistently activates the gastric mill rhythm in quiescent preparations.
甲壳类动物的口胃神经系统是一个经典模型，用于在细胞和网络层面理解调节离子电流和突触的作用。该系统中的口胃神经节包含两个不同的中央模式发生器：一个慢速胃磨网络，可产生灵活的节律输出（8 - 20秒），且通常处于静息状态；另一个快速幽门网络，可产生更一致的节律输出（0.5 - 2秒），在体外始终处于活跃状态。不同的离子电导决定了单个神经元的特性，进而影响幽门和胃磨网络的整体动态。然而，离子电流对幽门和胃磨网络不同动态的贡献尚未得到充分理解。本研究的目的是通过干扰正常的I 活动，评估口胃神经节中外向钾电流（I ）的变化如何影响幽门和胃磨节律的动态。我们通过浴用特异性I 阻滞剂4 - 氨基吡啶来降低其在体外口胃神经节中的作用，并定量评估两种节律的变化。我们发现，阻断口胃神经节中的I 会改变幽门神经元之间的同步性，并持续激活静止标本中的胃磨节律。
